Sampling points are used to penetrate a wail or ceiling and in operation are coupled to a capillary tube which is in turn connected to a pipe system distributed throughout a building or the like for drawing gas samples from the various sampling points to a pollution detection system.
It is important that the sampling points for smoke detectors are strategically positioned to ensure collection of smoke at the earliest possible moment. It is therefore possible or usual for the sample point to be located in conspicuous positions in the room of a building, necessitating good aesthetic appearance of the sampling point.
Furthermore it is important that the fitting of such sampling points is a relatively simple operation and yet the device must comply with various standards, for example Australian Standard 1670 which amongst other things calls for penetration of the sampling point for at least 25 mm into the space to be surveyed and the provision of a 50 mm identification ring in the case of use in smoke detection apparatus. It is an objective of the present invention to provide an improved sampling point construction complying with standard requirements has a minimum number of parts, and is simple to manufacture and install.